Construction of Precise Analysis System of Conoscopic Images in Liquid Crystals

液晶锥光图像精密分析系统的构建

• 批准号: 11555003
• 负责人: TAKEZOE Hideo
• 金额: $ 4.35万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11555003/
• 关键词: ferroelectric liquid crystal; conoscopic image; helical structure; 4x4 matrix method; ferrielectric phase; biaxiality; 反強誘電性液晶; 相構造; 工学異方性; 画像解析; 光学異方性

1. We constructed a system to observe conoscopic images using a He-Cd laser, which surves one of shortest wavelength light sources.2. We constructed a program for analyzing conoscopic images using the 4x4 matrix method.3. We observed helix unwinding processes in ferroelectric liquid crystals by an electric field in detail utilizing the constructed system, and obtained the following results.3-1. The experimental results agree with the simulation results by the 4x4 matrix method based on the field-induced helix unwinding process by elastic theory. Particularly, negative biaxiality was observed by the application of an electric field and was theoretically explained.3-2. So far, the negative biaxiality was thought to be characteristic in ferrielectric phases and was used to identify the ferrielectrie phase. However, we clarify that the field-induced negative biaxiality is generally observed in the ferroelectric phase and cannot be used to identify the ferrielectrie phases.3-3. We found that the previous conoscopic observation in MHPOBC, in which the antiferroelectric phase was first confirmed, was made using unsaficient field strength, that cannot induce complete helix unwinding. We reobserved the conoscopic images in detail by applying high fields saficient to induce complete helix unwinding. As results, we concluded that the helix unwinding process in MHPOBC cannot be explained only by considering ferroelectric interaction between the applying field and the polarization.

1. 我们构建了一个使用 He-Cd 激光器观察锥光图像的系统，该激光器可以使用最短波长的光源之一。 2．我们构建了一个使用4x4矩阵方法分析锥光图像的程序。 3．利用所构建的系统，我们详细观察了电场作用下铁电液晶中的螺旋解旋过程，并获得了以下结果。3-1．实验结果与基于弹性理论场致螺旋展开过程的4x4矩阵方法的模拟结果一致。特别是，通过施加电场观察到负双轴性，并从理论上解释了该现象。3-2．迄今为止，负双轴性被认为是亚铁电相的特征，并被用来识别亚铁电相。然而，我们澄清，场致负双轴性通常在铁电相中观察到，不能用于识别铁电相。3-3。我们发现，之前在 MHPOBC 中首次确认反铁电相的锥光观察是使用不充分的场强进行的，无法诱导完全的螺旋解旋。我们通过应用足以引起螺旋完全展开的高场来详细重新观察锥光图像。结果，我们得出结论，MHPOBC 中的螺旋展开过程不能仅通过考虑施加场和极化之间的铁电相互作用来解释。

项目成果

T.Akizuki et al.: "Molecular Orientational Sructures with Macroscopic Helix in Antiferroelectric Liquid Crystal Subphase"Japanese Journal of Applied Physics. Vol.38. 4832-4837 (1999)

T.Akizuki 等人：“反铁电液晶亚相中具有宏观螺旋的分子取向结构”日本应用物理学杂志。

T. Ogasawara, T. Akizuki, Y. Takanishi, K. Ishikawa and H. Takezoe: "Simulation of Conoscopic Figures Using 4 x 4 Matrix Method"Mol. Cryst. Liq. Cryst.. 362. 255-267 (2001)

T. Ogasawara、T. Akizuki、Y. Takanishi、K. Ishikawa 和 H. Takezoe：“使用 4 x 4 矩阵方法模拟锥光图形”Mol。

S.Suwa, Y.Takanishi, H.Hoshi, K.Ishikawa, H.Takezoe: "Helix unwinding process in the chiral smectic C phase of MHPOBC as observed by conoscopy"Liq. Cryst.. (submitted).

S.Suwa、Y.Takanishi、H.Hoshi、K.Ishikawa、H.Takezoe：“通过锥光观察观察到 MHPOBC 手性近晶 C 相中的螺旋解旋过程”Liq。

S. Suwa, Y. Takanishi, H. Hoshi, K. Ishikawa, and H. Takezoe: "Helix unwinding process in the chiral smectic C phase of MHPOBC as observed by conoscopy"Liq. Cryst.. (submitted).

S. Suwa、Y. Takanishi、H. Hoshi、K. Ishikawa 和 H. Takezoe：“通过锥光观察观察到 MHPOBC 手性近晶 C 相中的螺旋解旋过程”Liq。

S. Suwa, H. Hoshi, Y. Takanishi, K. Ishikawa, H.Takezoe and B. Zeks: "Helix Unwinding Process in a Short-Pitch Ferroelectric Liquid Crystal Mixture Studied by Conoscopy"Jpn. J. Appl. Phys.. (accepted).

S. Suwa、H. Hoshi、Y. Takanishi、K. Ishikawa、H. Takezoe 和 B. Zeks：“通过锥光检查研究短节距铁电液晶混合物中的螺旋展开过程”Jpn。